The role of Ga supersaturation on facet formation in the epitaxial lateral overgrowth of GaN
Abstract
In this paper, facet formation of (0001) {112¯0} {112¯2} facets during epitaxial lateral overgrowth (ELO) of GaN is investigated for different Ga vapor supersaturations. The ELO was conducted via metalorganic chemical vapor deposition on patterned GaN/sapphire templates with SiO2 masks aligned along the ⟨11¯00⟩ direction of GaN. Scanning electron microscopy was used to characterize the cross section shapes of the ELO GaN islands. A correlation of supersaturation, facet formation, and the shape of the ELO GaN islands is found. It is shown that {112¯2} facets are favored under high Ga vapor supersaturation, while {112¯0} facets are favored under low Ga vapor supersaturation. A qualitative model based on Wulff construction and density functional theory calculation is proposed to illustrate the mechanism of the facet formation of the ELO GaN islands.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 17, 2022
- Source ID
- 10.1063/5.0077628
Entities
People
- Ke Wang
- Pramod Reddy
- Ramón Collazo
- Ronny Kirste
- Seiji Mita
- Shun Washiyama
- W. J. Mecouch
- Zlatko Sitar
Organizations
- National Science Foundation
- North Carolina State University
- United States Army Research Laboratory